1 files changed, 140 insertions, 0 deletions
diff --git a/src/analyze/analyze-calendar.c b/src/analyze/analyze-calendar.c
new file mode 100644
index 0000000..6daab08
--- /dev/null
+++ b/src/analyze/analyze-calendar.c
@@ -0,0 +1,140 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "analyze.h"
+#include "analyze-calendar.h"
+#include "calendarspec.h"
+#include "format-table.h"
+#include "terminal-util.h"
+
+static int test_calendar_one(usec_t n, const char *p) {
+        _cleanup_(calendar_spec_freep) CalendarSpec *spec = NULL;
+        _cleanup_(table_unrefp) Table *table = NULL;
+        _cleanup_free_ char *t = NULL;
+        TableCell *cell;
+        int r;
+
+        r = calendar_spec_from_string(p, &spec);
+        if (r < 0) {
+                log_error_errno(r, "Failed to parse calendar specification '%s': %m", p);
+                time_parsing_hint(p, /* calendar= */ false, /* timestamp= */ true, /* timespan= */ true);
+                return r;
+        }
+
+        r = calendar_spec_to_string(spec, &t);
+        if (r < 0)
+                return log_error_errno(r, "Failed to format calendar specification '%s': %m", p);
+
+        table = table_new_vertical();
+        if (!table)
+                return log_oom();
+
+        assert_se(cell = table_get_cell(table, 0, 0));
+        r = table_set_ellipsize_percent(table, cell, 100);
+        if (r < 0)
+                return r;
+
+        assert_se(cell = table_get_cell(table, 0, 1));
+        r = table_set_ellipsize_percent(table, cell, 100);
+        if (r < 0)
+                return r;
+
+        if (!streq(t, p)) {
+                r = table_add_many(table,
+                                   TABLE_FIELD, "Original form",
+                                   TABLE_STRING, p);
+                if (r < 0)
+                        return table_log_add_error(r);
+        }
+
+        r = table_add_many(table,
+                           TABLE_FIELD, "Normalized form",
+                           TABLE_STRING, t);
+        if (r < 0)
+                return table_log_add_error(r);
+
+        for (unsigned i = 0; i < arg_iterations; i++) {
+                usec_t next;
+
+                r = calendar_spec_next_usec(spec, n, &next);
+                if (r == -ENOENT) {
+                        if (i == 0) {
+                                r = table_add_many(table,
+                                                   TABLE_FIELD, "Next elapse",
+                                                   TABLE_STRING, "never",
+                                                   TABLE_SET_COLOR, ansi_highlight_yellow());
+                                if (r < 0)
+                                        return table_log_add_error(r);
+                        }
+                        break;
+                }
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine next elapse for '%s': %m", p);
+
+                if (i == 0) {
+                        r = table_add_many(table,
+                                           TABLE_FIELD, "Next elapse",
+                                           TABLE_TIMESTAMP, next,
+                                           TABLE_SET_COLOR, ansi_highlight_blue());
+                        if (r < 0)
+                                return table_log_add_error(r);
+                } else {
+                        int k = DECIMAL_STR_WIDTH(i + 1);
+
+                        if (k < 8)
+                                k = 8 - k;
+                        else
+                                k = 0;
+
+                        r = table_add_cell_stringf_full(table, NULL, TABLE_FIELD, "Iteration #%u", i+1);
+                        if (r < 0)
+                                return table_log_add_error(r);
+
+                        r = table_add_many(table,
+                                           TABLE_TIMESTAMP, next,
+                                           TABLE_SET_COLOR, ansi_highlight_blue());
+                        if (r < 0)
+                                return table_log_add_error(r);
+                }
+
+                if (!in_utc_timezone()) {
+                        r = table_add_many(table,
+                                           TABLE_FIELD, "(in UTC)",
+                                           TABLE_TIMESTAMP_UTC, next);
+                        if (r < 0)
+                                return table_log_add_error(r);
+                }
+
+                r = table_add_many(table,
+                                   TABLE_FIELD, "From now",
+                                   TABLE_TIMESTAMP_RELATIVE, next);
+                if (r < 0)
+                        return table_log_add_error(r);
+
+                n = next;
+        }
+
+        return table_print(table, NULL);
+}
+
+int verb_calendar(int argc, char *argv[], void *userdata) {
+        int r = 0;
+        usec_t n;
+
+        if (arg_base_time != USEC_INFINITY)
+                n = arg_base_time;
+        else
+                n = now(CLOCK_REALTIME); /* We want to use the same "base" for all expressions */
+
+        STRV_FOREACH(p, strv_skip(argv, 1)) {
+                int k;
+
+                k = test_calendar_one(n, *p);
+                if (r == 0 && k < 0)
+                        r = k;
+
+                if (p[1])
+                        putchar('\n');
+        }
+
+        return r;
+}